The photoelectrochemical (PEC) behaviour of mono- and dinuclear complexes, [Ru(tap)(3)](2+) (tap = 1,4,5,8-tetraazaphenanthrene) and [Ru(phen)(2)](2)hat(4+) (phen = 1,10-phenanthroline; hat = 1,4,5,8,9,12-hexaazatriphenylene), incorporated in recast Nafion(R) on an SnO2 electrode, in contact with an aqueous solution containing a reducing agent such as hydroquinone (H(2)Q), is examined by two PEC methods : continuous and pulsed laser excitation. The PEC results combined with luminescence lifetime data obtained by diffuse reflectance from recast Nafion(R), lead to the evaluation of the quenching rate constant of the excited complex by H(2)Q in this medium. The luminescence inhibition by electron transfer from H(2)Q to the excited complex produces the reduced complex to which electroactivity is attributed, i.e. the origin of photocurrent and photopotential, and which has a lifetime in the ms time domain in the polyelectrolyte. Other explanations for such long electroactive intermediates are also proposed.